I see mostly in that spot complete bluffs, pocket pairs making an information raise, or Qx/55, so i don't like the 3bet without a better read, bloating the pot in that way ahead / way behind spot is usually going to result in a costly mistake. If you're 3betting it has to be because you expect to be able to get all-in with worse hands, which won't happen unless he's really really bad/bluffy/suspicious, trying to bully you around even tho you showed massive strength or putting you on a (suicidal) rebluff.

I usually call the flop minraise and check-reevaluate the turn. Most people with a pocket pair will either check back or make some kind of weird blockbet. If he has us beat he'll fire again almost always, likely big. If he's bluffing he might or might not follow through, hard to say without reads.

The more spastic you think the guy is the more you should be inclined to check/call down. If he's overall tight / straightforward you should just fold, sometimes even on the flop, tho these players sometimes inforaise pocket pairs too.